2 * linux/drivers/acorn/char/pcf8583.c
4 * Copyright (C) 2000 Russell King
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
10 * Driver for PCF8583 RTC & RAM chip
12 #include <linux/i2c.h>
13 #include <linux/slab.h>
14 #include <linux/string.h>
15 #include <linux/mc146818rtc.h>
16 #include <linux/init.h>
17 #include <linux/errno.h>
18 #include <linux/bcd.h>
22 static struct i2c_driver pcf8583_driver
;
24 static unsigned short ignore
[] = { I2C_CLIENT_END
};
25 static unsigned short normal_addr
[] = { 0x50, I2C_CLIENT_END
};
26 static unsigned short *forces
[] = { NULL
};
28 static struct i2c_client_address_data addr_data
= {
29 .normal_i2c
= normal_addr
,
35 #define DAT(x) ((unsigned int)(x->dev.driver_data))
38 pcf8583_attach(struct i2c_adapter
*adap
, int addr
, int kind
)
41 unsigned char buf
[1], ad
[1] = { 0 };
42 struct i2c_msg msgs
[2] = {
44 { addr
, I2C_M_RD
, 1, buf
}
47 c
= kmalloc(sizeof(*c
), GFP_KERNEL
);
51 memset(c
, 0, sizeof(*c
));
54 c
->driver
= &pcf8583_driver
;
56 if (i2c_transfer(c
->adapter
, msgs
, 2) == 2)
59 return i2c_attach_client(c
);
63 pcf8583_probe(struct i2c_adapter
*adap
)
65 return i2c_probe(adap
, &addr_data
, pcf8583_attach
);
69 pcf8583_detach(struct i2c_client
*client
)
71 i2c_detach_client(client
);
77 pcf8583_get_datetime(struct i2c_client
*client
, struct rtc_tm
*dt
)
79 unsigned char buf
[8], addr
[1] = { 1 };
80 struct i2c_msg msgs
[2] = {
81 { client
->addr
, 0, 1, addr
},
82 { client
->addr
, I2C_M_RD
, 6, buf
}
86 memset(buf
, 0, sizeof(buf
));
88 ret
= i2c_transfer(client
->adapter
, msgs
, 2);
90 dt
->year_off
= buf
[4] >> 6;
91 dt
->wday
= buf
[5] >> 5;
96 dt
->cs
= BCD_TO_BIN(buf
[0]);
97 dt
->secs
= BCD_TO_BIN(buf
[1]);
98 dt
->mins
= BCD_TO_BIN(buf
[2]);
99 dt
->hours
= BCD_TO_BIN(buf
[3]);
100 dt
->mday
= BCD_TO_BIN(buf
[4]);
101 dt
->mon
= BCD_TO_BIN(buf
[5]);
110 pcf8583_set_datetime(struct i2c_client
*client
, struct rtc_tm
*dt
, int datetoo
)
112 unsigned char buf
[8];
116 buf
[1] = DAT(client
) | 0x80;
117 buf
[2] = BIN_TO_BCD(dt
->cs
);
118 buf
[3] = BIN_TO_BCD(dt
->secs
);
119 buf
[4] = BIN_TO_BCD(dt
->mins
);
120 buf
[5] = BIN_TO_BCD(dt
->hours
);
124 buf
[6] = BIN_TO_BCD(dt
->mday
) | (dt
->year_off
<< 6);
125 buf
[7] = BIN_TO_BCD(dt
->mon
) | (dt
->wday
<< 5);
128 ret
= i2c_master_send(client
, (char *)buf
, len
);
132 buf
[1] = DAT(client
);
133 i2c_master_send(client
, (char *)buf
, 2);
139 pcf8583_get_ctrl(struct i2c_client
*client
, unsigned char *ctrl
)
146 pcf8583_set_ctrl(struct i2c_client
*client
, unsigned char *ctrl
)
148 unsigned char buf
[2];
154 return i2c_master_send(client
, (char *)buf
, 2);
158 pcf8583_read_mem(struct i2c_client
*client
, struct mem
*mem
)
160 unsigned char addr
[1];
161 struct i2c_msg msgs
[2] = {
162 { client
->addr
, 0, 1, addr
},
163 { client
->addr
, I2C_M_RD
, 0, mem
->data
}
170 msgs
[1].len
= mem
->nr
;
172 return i2c_transfer(client
->adapter
, msgs
, 2) == 2 ? 0 : -EIO
;
176 pcf8583_write_mem(struct i2c_client
*client
, struct mem
*mem
)
178 unsigned char addr
[1];
179 struct i2c_msg msgs
[2] = {
180 { client
->addr
, 0, 1, addr
},
181 { client
->addr
, 0, 0, mem
->data
}
188 msgs
[1].len
= mem
->nr
;
190 return i2c_transfer(client
->adapter
, msgs
, 2) == 2 ? 0 : -EIO
;
194 pcf8583_command(struct i2c_client
*client
, unsigned int cmd
, void *arg
)
197 case RTC_GETDATETIME
:
198 return pcf8583_get_datetime(client
, arg
);
201 return pcf8583_set_datetime(client
, arg
, 0);
203 case RTC_SETDATETIME
:
204 return pcf8583_set_datetime(client
, arg
, 1);
207 return pcf8583_get_ctrl(client
, arg
);
210 return pcf8583_set_ctrl(client
, arg
);
213 return pcf8583_read_mem(client
, arg
);
216 return pcf8583_write_mem(client
, arg
);
223 static struct i2c_driver pcf8583_driver
= {
225 .id
= I2C_DRIVERID_PCF8583
,
226 .flags
= I2C_DF_NOTIFY
,
227 .attach_adapter
= pcf8583_probe
,
228 .detach_client
= pcf8583_detach
,
229 .command
= pcf8583_command
232 static __init
int pcf8583_init(void)
234 return i2c_add_driver(&pcf8583_driver
);
237 __initcall(pcf8583_init
);